For older women, cheaper methods of detecting breast cancer may be as good as more expensive ones, according to the latest research.

Medicare spending on breast cancer screenings like mammograms adds up to just over $1 billion each year, but how effective is that spending in treating tumors?

In a study published in JAMA Internal Medicine Dr. Cary Gross, an associate professor of internal medicine at Yale School of Medicine and director of the Cancer Outcomes, Public Policy, and Effectiveness Research (COPPER) Center at Yale and his colleagues studied national estimates for breast cancer screening costs and compared these to screening outcomes.

They reviewed results from more than 137,200 female Medicare beneficiaries between the ages of 66 to 100 without any history of breast cancer before 2006. The team followed the women for two years and monitored their screenings, cancer diagnoses and costs.

They found that spending for breast cancer screening varied widely across the country, ranging from $40 to $110 per woman. Higher costs came primarily from newer screening technologies such as digital mammograms and computer-aided detection. And the more expensive screens also seemed to come with a higher health price: women living in regions with higher screening costs were 78% more likely to be diagnosed with early breast cancer.

That suggest that the more advanced screening methods are picking up smaller tumors at earlier stages, which is the goal of screening. Indeed these women were less likely than those living in areas where screening costs were lower to have advanced stage cancers detected. But that doesn’t necessarily mean that the higher costs of screening are justified. For women of this age group, these diagnoses could lead to unnecessary treatment for cancers that would never harm them during their lifetime. That’s the reason that the U. S. Preventative Task Force (USPTF) last year loosened its recommendation for regular mammogram screening for women aged 75 and older; they concluded there was a lack of evidence that the cost and potential complications of screening at this age is justified.

Gross and his colleagues found that women in this age group spend over $410 million every year on breast cancer screening, and that women living in regions with higher screening costs also paid more for treatments—nearly $500 million in total—generated by the tests. Earlier detection is ideally supposed to lead to less expensive care, since patients are treated for less advanced disease, but that’s not what the researchers found. Medicare reimbursements support the new modalities and technologies that the scientists say are not rigorously evaluated for cost and outcomes.

“I’m not saying we shouldn’t be screening, I’m just saying there is no evidence to base our decisions on it,” says Gross. “We are not saying that digital mammography is not good or it is good. All we are saying is that it is more expensive. We are employing these new and more expensive techniques and we are not really sure it’s helping women.”

In a corresponding editorial, Jeanne Mandelblatt, associate director for population sciences at the Lombardi Comprehensive Cancer Center at Georgetown University explained that new technologies are not necessarily associated with higher benefit costs for women because the devices are made to look at dense breasts, which are more common among younger women before menopause. For older women, traditional mammograms, which are cheaper than the digital versions, may be just as effective in picking up potential tumors.

“At the end of the day, this is not really about cost as the primary concern. No woman wants to undergo a test that may do her more harm than good,” says Gross. “We need better evidence to help a woman make informed decisions about her screening and also we need better evidence to help policy-makers make decisions on how we can efficiently decrease the burden of breast cancer in the population.” Less, it seems, is sometimes more.